Our annual CoCoRaHS recruitment campaign has a new name and a new month! Beginning April 1, the Rain Gauge Rally invites volunteers across the country to join the network and track precipitation in their yard.
This friendly, state-against-state contest aims to see which state can recruit the most new observers during April. Help support our state and be part of the effort to bring home the coveted CoCoRaHS Cup!
Spring is a great time to get started—April showers might just bring new observers!
Weather/Precipitation Observers Needed!
Observers are needed in many counties throughout Indiana. Ideally, in order to get the spatial resolution desired we need at least 10 observers per county. The majority of counties have less than this. As of March 17, 2026 there were 5 or fewer active observers over the past 6 months in the following counties (listed from north to south; observer number in parentheses):
Please consider joining and telling your fellow Hoosiers of the need! Below is information about the program and how to join. |
What is CoCoRaHS?
CoCoRaHS is an acronym for Community Collaborative Rain, Hail, and Snow Network. CoCoRaHS is a non-profit community based network of volunteers of all ages and backgrounds working together to measure precipitation. The network originated at Colorado State University in 1988 and has expanded to many thousands of observers throughout the United States and beyond. Watch this short video for a great, quick overview of the program.
Why is CoCoRaHS needed?
High-quality, localized precipitation data is essential for accurate weather analysis, forecasting, warnings, and decision-making. NWS and FAA observing stations alone cannot capture the full variability of rain, snow, and hail across communities. Volunteer observers fill these critical gaps by providing timely, ground-truth measurements that support a wide range of users, such as agriculture, emergency management, insurance, research, and water resource management, and many others.
For example, during the January 25–26, 2026 snowstorm, CoCoRaHS observers supplied snowfall reports that helped emergency managers document impacts and justify financial aid requests for recovery. At the same time, the National Weather Service relied on this data to verify winter storm warnings and improve future forecasts. From agricultural interests to zoning and planning, this kind of real-time, community-driven information makes CoCoRaHS an invaluable part of the nation’s weather and hazard response infrastructure.
Who can participate?
This is a community project. Everyone can help. The only requirements are: 1) access to the CoCoRaHS website to submit your report, 2) an approved rain gauge (you can purchase one from the CoCoRaHS Store), and 3) enthusiasm for watching and reporting weather conditions, as well as a desire to learn more about how weather can effect our lives. The ultimate goal of the program is to have one observer per square mile in urban/suburban areas and one observer every 36 square miles in rural areas.
Once trained, volunteers collect data using tools such as a 4-inch diameter rain gauge (see picture below).
How does one join?
Visit the CoCoRaHS home page and fill out an application. All new observers in Indiana are encouraged to attend a training session, either a live session/walk-in training session (such as with a county coordinator) or online training via the CoCoRaHS website. Please see the Indiana page on the CoCoRaHs site for more information. Online training slideshows and videos are available on the CoCoRaHS page and on the NWS Indianapolis YouTube page.
CoCoRaHS in Indiana is made possible by: The Indiana State Climate Office at Purdue University and the National Weather Service office in Indianapolis.
Training
Check our state page on the CoCoRaHS website for upcoming and recently recorded online training sessions.
Check out this locally produced training video on YouTube: CoCoRaHS Training
Follow us on X
Follow us on Facebook
Follow us on YouTube
IND RSS Feed